Adaptive cruise speed controlling apparatus and method for automotive vehicle

• US 6,870,468 B2
• Filed: 08/13/2003
• Issued: 03/22/2005
• Est. Priority Date: 09/27/2002
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Sugano, Takeshi
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Stone, Jennifer
• Application Number:
  US10/639,634
• Publication Number:
  US 20040064240A1
• Time in Patent Office: 587 Days
• Field of Search: 340/435, 340/425.5, 180/274, 180/277, 180/271, 701/96
• US Class Current: 340/435
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60W 2050/0012 Feedforward or open loop systems
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

In adaptive cruise speed controlling apparatus and method for an automotive vehicle, a target vehicular velocity is set in such a way that an addition value of a difference between a target inter-vehicle distance from the vehicle to a preceding vehicle, the preceding vehicle running ahead of the vehicle on the same traffic lane, and an actual inter-vehicle distance thereof multiplied by a first gain and a relative velocity between the vehicle and the preceding vehicle multiplied by a second gain is included in the set vehicular velocity and the first and second gains are set to control a vehicular driving force to make the inter-vehicle distance substantially equal to the target inter-vehicle distance and to converge the inter-vehicle distance into the target inter-vehicle distance within a predetermined small overshoot crossing the target inter-vehicle distance when a size of an external form of the preceding vehicle is larger than a predetermined size.

Claims

1. An adaptive cruise speed controlling apparatus for an automotive vehicle, comprising:

a target vehicular velocity setting section that sets a target vehicular velocity in such a way that an addition value of a difference between a target inter-vehicle distance from the vehicle to a preceding vehicle, the preceding vehicle running ahead of the vehicle on the same traffic lane, and an actual inter-vehicle distance thereof multiplied by a first gain and a relative velocity between the vehicle and the preceding vehicle multiplied by a second gain is included in the set vehicular velocity; and

a control gain setting section that sets the first and second gains to control a vehicular driving force to make the inter-vehicle distance substantially equal to the target inter-vehicle distance and to converge the inter-vehicle distance into the target inter-vehicle distance within a predetermined small overshoot crossing the target inter-vehicle distance when a size of an external form of the preceding vehicle is larger than a predetermined size.

2. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 1, wherein the first and second gains are set on the basis of both of a damping coefficient and a specific angular frequency and the specific angular frequency is set to be within a predetermined small angular frequency value when the size of the external form of the preceding vehicle is larger than the predetermined size.

3. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 1, wherein the control gain setting section sets the first and second gains on the basis of predetermined damping coefficient and predetermined specific angular frequency, the predetermined damping coefficient being set to be in excess of a predetermined large damping coefficient value when the size of the external form of the preceding vehicle is larger than the predetermined size.

4. An adaptive cruise speed controlling apparatus for an automotive vehicle, comprising:

a target inter-vehicle distance setting section that sets a target inter-vehicle distance between the vehicle and a preceding vehicle which is running ahead of the vehicle at the same traffic lane;

an inter-vehicle distance detecting section that detects an actual inter-vehicle distance between the vehicle and the preceding vehicle;

a relative velocity detecting section that detects a relative velocity of the vehicle to the preceding vehicle;

a target vehicular velocity setting section that sets a target vehicular velocity in such a way that an addition value between a value of difference between the target inter-vehicle distance set by the target inter-vehicle distance setting section and the inter-vehicle distance detected by the inter-vehicle distance detecting section multiplied with a first gain and a value of a second gain multiplied with the relative velocity detected by the relative velocity detecting section is included in the set vehicular velocity;

a vehicular velocity detecting section that detects the vehicular velocity of the vehicle;

a vehicular driving force controlling section that controls a vehicular driving force to make the inter-vehicle distance detected by the inter-vehicle distance detecting section substantially equal to the target inter-vehicle distance set by the target inter-vehicle distance setting section and to converge the inter-vehicle distance detected by the inter-vehicle distance detecting section into the target inter-vehicle distance set by the target inter-vehicle distance setting section; and

a preceding vehicle external form detecting section that detects a magnitude of an external form of the preceding vehicle, the target vehicular velocity setting section setting the first and second gains in such a manner that the inter-vehicle distance is smoothly converged within a predetermined small overshoot crossing the target inter-vehicle distance into the target inter-vehicle distance when the magnitude of the external form of the preceding vehicle detected by the preceding vehicle external form detecting section is larger than a predetermined magnitude.

5. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 4, wherein the target vehicular velocity setting section sets the first and second gains on the basis of predetermined damping coefficient and specific angular frequency, the specific angular frequency being set to be a predetermined small specific angular frequency value when the magnitude of the external form of the preceding vehicle detected by the preceding vehicle external form detecting section is larger than a predetermined magnitude.

6. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 4, wherein the target vehicular velocity setting section sets the first and second gains on the basis of predetermined damping coefficient and specific angular frequency, the predetermined damping coefficient being set to be larger than a predetermined large damping coefficient value when the magnitude of the external form of the preceding vehicle is larger than the predetermined magnitude.

7. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 4, wherein the preceding vehicle external form detecting section detects an area of the external form of the preceding vehicle and the target vehicular velocity setting section sets the first and second gains in such a manner that the inter-vehicle distance is more smoothly converged with a predetermined small overshoot crossing the target inter-vehicle distance into the target inter-vehicle distance as the area of the external form of the preceding vehicle becomes larger.

8. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 7, wherein the preceding vehicle external form detecting section detects the area of the preceding vehicle and the first and second gains are set in such a manner that, as the area of the external form becomes wider, the inter-vehicle distance is more smoothly converged within a predetermined small overshoot crossing the target inter-vehicle distance and the first and second gains are set on the basis of predetermined damping coefficient and specific angular frequency, the predetermined specific angular frequency being set to be smaller than a predetermined small predetermined specific angular frequency value as the area of the external form of the preceding vehicle becomes wide.

9. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 7, wherein the preceding vehicle external form detecting section detects an area of an external form of the preceding vehicle and the target vehicular velocity setting section sets the damping coefficient to be larger as the area of the external form of the preceding vehicle becomes wider.

10. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 4, wherein the target vehicular velocity setting section sets the target vehicular velocity (V*) as follows:

V*=V−

fd(L*−

L)+(1−

fv)Δ

V, wherein V denotes the vehicular velocity, fd denotes the first gain, L* denotes the target inter-vehicle distance, L denotes the detected inter-vehicle distance, fv denotes the second gain, and Δ

V denotes the relative velocity.

11. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 10, wherein V+Δ

V=V_T, wherein V_T denotes a vehicular velocity of the preceding vehicle and the target vehicular velocity (V*) is also expressed as V*=V_T−

fd·

(L*−

L)−

fv·

Δ

V.

12. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 11, wherein the relative velocity detecting section (Δ

V) includes a band pass filter (BPF) to detect the relative velocity from the actual inter-vehicle distance (L), the band pass filter having a transfer function F(s) as F(a)=ω

c²/(s²+2ζ

ω

cs+ω

c²), wherein ω

c=2π

fc and fc denotes a cutoff frequency of the band pass filter, ζ

denotes the damping coefficient, and s denotes a Laplace transform operator.

13. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 12, wherein the first gain fd=ω

n²·

τ

v and the second gain fv=1−

2ζ

ω

n·

τ

v, wherein τ

v denotes a time constant of a vehicular servo system.

14. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 13, wherein a rear surface area of the preceding vehicle becomes larger, the damping coefficient (ζ

) is set to be larger, the second gain (fv) is set to be larger, and a relative velocity gain (Δ

V) in the calculation equation of the target vehicular velocity (V*) is set to be larger so that when the vehicular velocity is in excess of the vehicular velocity of the preceding vehicle (V_T), target vehicular velocity (V*) is remarkably reduced, the overshoot crossing the target inter-vehicle distance L* to approach to the preceding vehicle is reduced.

15. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 14, wherein the damping coefficient (ζ

) is set in such a manner that a correction coefficient (K) which is larger than one is multiplied with a predetermined damping coefficient candidate (ζ

′

).

16. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 13, wherein, as a rear surface area of the preceding vehicle becomes larger, the predetermined specific angular frequency (ω

n) is set to be smaller, the first gain is set to become smaller, the second gain fv is set to become larger, and a convergence characteristic of the target inter-vehicle distance (L*) becomes more moderate so the approaching vehicular velocity to the preceding vehicle becomes relatively slow.

17. An adaptive cruise speed controlling apparatus for an automotive vehicle as claimed in claim 16, wherein the specific angular frequency (ω

n) is set in such a manner that a correction coefficient (K) which is smaller than one is multiplied with a predetermined specific angular frequency candidate (ω

n′

).

18. An adaptive cruise speed controlling apparatus for an automotive vehicle, comprising:

target inter-vehicle distance setting means for setting a target inter-vehicle distance between the vehicle and a preceding vehicle which is running ahead of the vehicle at the same traffic lane;

inter-vehicle distance detecting means for detecting an actual inter-vehicle distance between the vehicle and the preceding vehicle;

relative velocity detecting means for detecting a relative velocity of the vehicle to the preceding vehicle;

target vehicular velocity setting means for setting a target vehicular velocity in such a way that an addition value between a value of difference between the target inter-vehicle distance set by the target inter-vehicle distance setting means and the inter-vehicle distance detected by the inter-vehicle distance detecting means multiplied with a first gain and a value of a second gain multiplied with the relative velocity detected by the relative velocity detecting means is included in the set vehicular velocity;

vehicular velocity detecting means for detecting the vehicular velocity of the vehicle;

vehicular driving force controlling means for controlling a vehicular driving force to make the inter-vehicle distance detected by the inter-vehicle distance detecting means substantially equal to the target inter-vehicle distance set by the target inter-vehicle distance setting means and to converge the inter-vehicle distance detected by the inter-vehicle distance detecting means into the target inter-vehicle distance set by the target inter-vehicle distance setting means; and

preceding vehicle external form detecting means for detecting a magnitude of an external form of the preceding vehicle, the target vehicular velocity setting means setting the first and second gains in such a manner that the inter-vehicle distance is smoothly converged within a predetermined small overshoot crossing the target inter-vehicle distance into the target inter-vehicle distance when the magnitude of the external form of the preceding vehicle detected by the preceding vehicle external form detecting means is larger than a predetermined magnitude.

19. An adaptive cruise speed controlling method for an automotive vehicle, comprising:

setting a target vehicular velocity in such a way that an addition value of a difference between a target inter-vehicle distance from the vehicle to a preceding vehicle, the preceding vehicle running ahead of the vehicle on the same traffic lane, and an actual inter-vehicle distance thereof multiplied by a first gain and a relative velocity between the vehicle and the preceding vehicle multiplied by a second gain is included in the set vehicular velocity; and

setting the first and second gains to control a vehicular driving force to make the inter-vehicle distance substantially equal to the target inter-vehicle distance and to converge the inter-vehicle distance into the target inter-vehicle distance with a relatively small overshoot crossing the target inter-vehicle distance when a size of the preceding vehicle is larger than a predetermined size.

20. An adaptive cruise speed controlling method for an automotive vehicle, comprising:

setting a target inter-vehicle distance between the vehicle and a preceding vehicle which is running ahead of the vehicle at the same traffic lane;

detecting an actual inter-vehicle distance between the vehicle and the preceding vehicle;

detecting a relative velocity of the vehicle to the preceding vehicle;

setting a target vehicular velocity in such a way that an addition value between a value of difference between the set target inter-vehicle distance and the detected inter-vehicle distance multiplied with a first gain and a value of a second gain multiplied with the detected relative velocity is included in the set vehicular velocity;

detecting the vehicular velocity of the vehicle;

controlling a vehicular driving force to make the detected inter-vehicle distance substantially equal to the set target inter-vehicle distance and to converge the detected inter-vehicle distance into the set target inter-vehicle distance; and

detecting a magnitude of an external form of the preceding vehicle, at the target vehicular velocity setting, the first and second gains being set in such a manner that the inter-vehicle distance is smoothly converged within a predetermined small overshoot crossing the target inter-vehicle distance into the target inter-vehicle distance when the detected magnitude of the external form of the preceding vehicle is larger than a predetermined magnitude.